Improvement in automatic air-escapes for railway air-brakes



1. FORD, a. WESTINGHOUSE, lr., & T. W. WELSH Automatic Air-Escape forRailway Air-Brakes;

Patented April 27,1875.

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UNITED STATES PATENT {OFFICE WALTER J. FORD, OF ADRIAN, MICHIGAN, ANDGEORGE WESTINGHOUSE, JR, AND THOMAS W. WELSH, OF PITTSBURG,PENNSYLVANIA.

IMPROVEMENT lN AUTOMATIC AlR-ESCAPES FOR RAILWAY AIR-BRAKES.

Specification forming part of Letters Patent No. 162,465, dated April27, 1875; application filed April 2, 1875.

To all whom it may concern:

Be it known that we, .WALTER J. FORD, of Adrian, county of Lenawee,State of Michigan, and GEORGE XVEsTINeHoUsE, Jr., and THOMAS W. WELSH,both ofPittsburg, county of Allegheny, State of Pennsylvania,-haveinvented or discovered a new and useful Improvement in AutomaticAir-Escape for Railway Air-Brakes; and we do hereby declare thefollowing to be a full, clear, concise, and exact description thereof,reference being had to the accompanying drawing making a part of thisspecification, in which like letters indicate like parts.

Figures 1 and 2 are sectional views of our improvement in differentforms of its application, and Fig. 3 is a view in outline illustrativeof the system of apparatus to which it is applied.

At B, Fig. 3, we have shown the main reservoir, such as is used inair-brake apparatus for containing compressed air. From this thebrake-pipe pleads back beneath the cars, with the usual flexible hoseand coupling between cars, and from it a branch pipe, 1), leads to eachbrake-cylinder P.

The object of our invention is to provide for the more immediate escapeof the compressed air from the brake-cylindes after it has done itswork,instead of passing it back to the three way cock in on thelocomotive. For this purpose we attach to the brake-pipe p or branch 19of one or more cars of a train, as at r, Fig.

3, a device, shown in sectional view in Fig. 1,

or in a modified form in Fig. 2. This device consists of the T-piece A,Fig. l, to the bottom of which is attached a small reservoir, B, whichscrews into the lower part of the T-piece A. The lower part of theT-piece is provided with the valve 0, having an annular V-shaped seat onits bottom face, and at its lower end provided with a cylindrical guide,a, sliding in the chamber n. The valve 0 is also provided with three ormore wings to act as guides. Ports a communicate with the atmospherefrom the chamber a between the valve 0 and the guide a. Introducedbetween'the pieces A and B is an india-rubber diaphragm, b, which isfirmly held between the two pieces. The valve 0 is of such length thatwhen the annular V-shaped seat rests upon the shoulder in-the piece Athe end a presses upon the rubber 12, causing it to have a depressiondownward. Through the center of the valve 0 is drilled a small hole, inwhich is inserted a wire, b somewhat smaller than the hole, this wirepermitting a limited amount of air to pass from the main piece A,through the valve 0, into the chamber B. This wire b is, preferably,somewhat shorter than the distance between the cap A and the crossbar B,arranged in the chamber B, and permits of the valve 0 sliding up anddown on the wire.

The operation of the device is as follows: When air is admitted to thebrake-pipe the pipes are charged, and at the same time a limited portionof the air flows through the valve 0 around the'wire b filling thechamber B to the same pressure as in the pipe. The pressure from thechamber B is prevented from escaping to the atmosphere through the portsa by the rubber disk I) pressing against the lower part a of the valve0. The area of the valve 0 subject to downward pressure is somewhatlarger than the effective area of the diaphragm pressing against thelower end of the valve. Consequently the valve 0, when there is anequilibrium of pressure in the brake-pipe and chamber B, remains on itsseat. When air is discharged from the brake-pipe for the purpose ofreleasing the brakes, the pressure within the chamber B, being preventedfrom escaping as rapidly as from the pipe A by the smallness of theopening around the wire b exerts a pressure on the rubber diaphragm b,which causes the valve 0 to be raised from its seat, and the air to bemore rapidly discharged from the brake-cylinders and brake-pipe aroundthe wings of the valve 0, and through the ports a to the atmosphere. Thewire I) is so proportioned in relation to the size of the hole in thevalve 0 that the pressure within the chamber B will, after the brakesare off, be discharged very soon, so that when the brakes are again tobe applied the pressure will have escaped from the chamber and permitthe valve 0 to be closed. The cap A in the part A is made large enoughfor the valve 0 to be inserted, and under the valve 0 is provided a softrubber or metal seat to make an airtight joint to prevent the escape ofair.

Fig. 2 represents a modification of the same, in which a thin metaldiaphragm is used in place of the rubber diaphragm b, Fig. 1. The mainpart A is similar in construction to the one shown in Fig. 1. A flexiblemetallic diaphragm, W, is held between the parts B and A, and the jointis made air-tight to prevent the escape of air by the insertion ofrubber rings each side of the diaphragm. Through the center of thediaphragm is screwed a small piece, b through which is drilled a smallhole fitted with a wire similar to that in the valve U, Fig. l. Acommunication is made from the chamber m, above the diaphragm 11 to thethrough passageway in A by the port a shown in dotted lines. The part Ais provided with a valve, 0, seated upon a soft-metal or rubber seat,and beneath this valve is the chamber a, having discharge-ports aleading to the atmosphere, as before.

The operation will then be as follows: Air enters the brake-pipe andpasses through the port a to the upper side of the diaphragm b passingthrough the center piece 11 around the wire I) to the reservoir B. Whenthe air is discharged from the brake-pipe, the pressure, acting from thereservoir B on the under side of the diaphragm b raises the valve 0 fromits seat by acting against the valve-stem b and thus permitting the airto escape from'the brake-cylinders and brake-pipe around the valve 0,and through the ports a to the atmosphere, and the excess of pressure inthe reservoir B will leak out as before.

The size of the reservoir may be varied at pleasure, but for mostpurposes one having from ten to twenty cubical inches of space, more orless, will do the work desired.

The like device may be arranged directly on the brake-cylinder, if sopreferred, but that described we believe to be the best.

What we claim as our invention is- 1. In combination with a brake-pipeor cylinder, an airreservoir, B, arranged to be charged with compressedair while the brakes are be ing applied, an intermediate valve to beopened by the back pressure of the air in such reservoir when the brakesare being released, and an air-escape port or ports forthe escape of theair on the opening of the valve, such valve being opened against thepressure of the escaping air, substantially as set forth.

2. As an attachment for the brake-pipe or cylinder, the piece A,containing a chamber, a, with valve 0 at one end, a reservoir, B, at theother, a communicating charging-port, and an intermediate escape-port,substantially as set forth.

, 3. In combination with the brake-pipe or cylinder, the reservoir B andair-charging port, a valve, 0, arranged intermediate between thereservoir and an otherwise unobstructed source of supply, and closingthe escape by air-pressure simultaneously with the application of thebrakes and the charging of the reservoir, substantially as set forth.

In testimony whereof we. have hereunto set our hands.

WVALTER J. FORD. GEORGE WESTINGHOUSE, J R. T. W. WELSH. Witnesses:

J OHN D. MORELAND, H. HERMAN WESTINGHOUSE.

